This invention relates, in general, to a shoe parts assembly and manufacturing device and, in particular, to a new and useful workbench for assembling parts which must be joined together, for example, by adhesive or by sewing. The invention is also directed to a method of effecting the joining of these parts.
The present invention particularly pertains to a workbench for preparing a two- dimensional compound workpiece comprising both a lower part and at least one upper part placed on it in a predetermined orientation, for example, a shoe upper with a plurality of parts, comprising a bench plate for receiving the lower part.
Parts of shoe uppers are currently still assembled by stitching on conventional sewing machines with manual handling of the upper or its individual parts. Numerically controlled, programmable automatic sewing machines are used only to produce decorative stitchings and in the case of high lot numbers.
Shoe uppers very often comprise a plurality of parts, especially when the shoe uppers are provided with small trimming parts. There are often periods of interruption when stitching such shoe uppers, because the parts of the upper to be connected to one another must constantly be readjusted with respect to one another. This happens especially when the parts to be sewn on, e.g., the above-mentioned trimming parts, are relatively small.
The present invention is based on the consideration that such alignment processes during stitching and the resulting periods of interruption can be almost completely or completely avoided if the parts of the shoe upper are already fixed before stitching, e.g., by gluing. However, this requires that the adhesive be cleanly applied to the individual parts of the shoe upper along defined contours and that the parts of the shoe upper be placed on each other in their final mutual position, without any subsequent alignment being necessary, because such subsequent alignment could cause visible traces of adhesive.